Numerous dispersion methods have so far been proposed for uniformly dispersing a liquid and another liquid, a liquid and a solid, or a solid and another solid to thereby obtain a dispersion in a liquid or powder state, or in a molten state as the case may be, and many apparatuses based on those methods have been developed.
The mixing and dispersing apparatuses that are known include mechanical mixing and kneading apparatuses, such as a roll mill, an extruder, a kneader, and a Henschel mixer. These mechanical mixing and kneading apparatuses rotate a vane that serves as a rotary mixing and stirring bar in a cavity at a high speed, so as to squeeze a material to be dispersed into the gap between the vane and the cavity or to apply an impact force of the vane to the material to be dispersed containing a dispersion medium, an additive and so on for mixing and dispersing, and the material to be dispersed is turbulent-stirred.
Patented documents 1 to 4 disclose a batch mixer including a vane that rotates at a high speed to work as a rotary mixing and stirring bar, to thereby stir a material to be dispersed with the vane thus giving a uniform dispersion.
Further, patented documents 5 and 6 disclose a softening/melting type mixing and kneading apparatus, which mixes and stirs a thermoplastic resin and a coloring agent, which are the material to be dispersed, to thereby soften or melt the thermoplastic resin utilizing frictional heat generated in this process, thus giving a uniform dispersion containing the thermoplastic resin and the coloring agent.
Patented document 7 discloses an apparatus that mixes and disperses an organic pigment and a resin injected into a gap between disk-shaped plates, in a description of a method of dispersing the organic pigment in the resin, and the dispersion methods described in those patented documents are all based on the turbulent-stirring.    [Patented document 1] U.S. Pat. No. 3,266,738    [Patented document 2] U.S. Pat. No. 4,230,615    [Patented document 3] JP-B No. S64-4892    [Patented document 4] JP-A No. H10-151332    [Patented document 5] JP-A No. 2001-105426    [Patented document 6] JP-A No. 2001-105427    [Patented document 7] JP-A No. 2000-167826